; 注释: .ll文件中注释以';'开头
; ModuleID = 'easy.c'
source_filename = "easy.c"
; 注释: target的开始
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; 注释: target的结束

define dso_local i32 @callee(i32 %0) #0 {
;自定义函数必须从%2开始书写
;为a创建一个地址
  %2 = alloca i32, align 4
  ;把参数赋值给a
  store i32 %0, i32* %2, align 4
  ;读取a到寄存器
  %3 = load i32, i32* %2, align 4
  ;计算乘法
  %4 = mul nsw i32 2, %3
  ret i32 %4;返回
}

define dso_local i32 @main() #0 {
    ;默认的%1
  %1 = alloca i32, align 4
  store i32 0, i32* %1, align 4
  %2 = call i32 @callee(i32 110);调用函数
  ret i32 %2
}

attributes #0 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

!llvm.module.flags = !{!0}
!llvm.ident = !{!1}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang version 10.0.1 "}